Jackson sample with deep field filter

App.java

public class App {

    public static void main(String[] args) {
        Type type = new Type("hg", "Mercurial");
        Repository repository = new Repository("42", "scm", type, "SCM-Manager", "SCM-Manager Repository Hosting");

        System.out.println(JSON.asString(repository));
        System.out.println(JSON.asString(repository, "id", "desc"));
        System.out.println(JSON.asString(repository, "id", "name", "type", "type.name", "displayName"));
    }

}

JSON.java

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.JsonStreamContext;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.introspect.Annotated;
import com.fasterxml.jackson.databind.introspect.AnnotationIntrospectorPair;
import com.fasterxml.jackson.databind.introspect.JacksonAnnotationIntrospector;
import com.fasterxml.jackson.databind.ser.PropertyFilter;
import com.fasterxml.jackson.databind.ser.PropertyWriter;
import com.fasterxml.jackson.databind.ser.impl.SimpleBeanPropertyFilter;
import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
import com.fasterxml.jackson.databind.type.TypeFactory;
import com.fasterxml.jackson.module.jaxb.JaxbAnnotationIntrospector;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

/**
 * Sample filtering fields durring json marshalling.
 * 
 * @author Sebastian Sdorra
 */
public class JSON {
    
    private static final String DEFAULT_FILTER = "__default";
    private static final String DOT = ".";

    private static final ObjectMapper MAPPER = new ObjectMapper().setAnnotationIntrospector(
            new AnnotationIntrospectorPair(
                    new FilteringAnnotationInpector(), new JaxbAnnotationIntrospector(TypeFactory.defaultInstance())
            )
    );

    public static String asString(Object object, String... fields) {
        PropertyFilter filter = filter(fields);
        SimpleFilterProvider provider = new SimpleFilterProvider();
        provider.addFilter(DEFAULT_FILTER, filter);
        try {
            return MAPPER.writer(provider).writeValueAsString(object);
        } catch (JsonProcessingException ex) {
            throw new RuntimeException("failed to marshall", ex);
        }
    }

    private static PropertyFilter filter(String[] fields) {
        PropertyFilter filter;
        if (fields.length > 0) {
            Set<String> properties = new HashSet<>(fields.length);
            Collections.addAll(properties, fields);
            filter = new DeepFieldFilter(properties);
        } else {
            filter = SimpleBeanPropertyFilter.serializeAll();
        }
        return filter;
    }

    private static class FilteringAnnotationInpector extends JacksonAnnotationIntrospector {

        private static final long serialVersionUID = -8722016441050379430L;

        @Override
        public String findFilterId(Annotated a) {
            return DEFAULT_FILTER;
        }

    }

    private static class DeepFieldFilter extends SimpleBeanPropertyFilter {

        private final Set<String> includes;

        private DeepFieldFilter(Set<String> includes) {
            this.includes = includes;
        }

        private String createPath(PropertyWriter writer, JsonGenerator jgen) {
            StringBuilder path = new StringBuilder();
            path.append(writer.getName());
            JsonStreamContext sc = jgen.getOutputContext();
            if (sc != null) {
                sc = sc.getParent();
            }

            while (sc != null) {
                if (sc.getCurrentName() != null) {
                    if (path.length() > 0) {
                        path.insert(0, DOT);
                    }
                    path.insert(0, sc.getCurrentName());
                }
                sc = sc.getParent();
            }
            return path.toString();
        }

        @Override
        public void serializeAsField(Object pojo, JsonGenerator gen, SerializerProvider provider, PropertyWriter writer)
                throws Exception {
            String path = createPath(writer, gen);
            if (includes.contains(path)) {
                writer.serializeAsField(pojo, gen, provider);
            } else {
                writer.serializeAsOmittedField(pojo, gen, provider);
            }
        }

    }
}

@sdorra Under which license are you publishing these code snippets?
Are the snippets free to use (something like MIT license) or how should I attribute you, when I use your snippets?

Most of my OSS Code is published under the MIT License. Feel free to use this code for what ever you like. I don't know if i can set a license for a gist.

@sdorra Under which license are you publishing these code snippets?
Are the snippets free to use (something like MIT license) or how should I attribute you, when I use your snippets?

Most of my OSS Code is published under the MIT License. Feel free to use this code for what ever you like. I don't know if i can set a license for a gist.

Thank you.
I have seen a few gists where there is an additional field named LICENSE.
Or you can also create an extra gist like https://gist.github.com/martinbuberl/c0de29e623a1e34d1cda7e817d18bafe.